Portable devices, such as mobile phones (e.g., cell phones), are becoming increasingly common. These portable devices have grown more complex over time, incorporating many features, including, for example, MP3 player capabilities, web browsing capabilities, capabilities of personal digital assistants (PDAs) and the like. Most of these devices include device jacks into which a headset or headphones may be plugged. In some cases, the headsets include, in addition to earphones for listening to output of the host device, a microphone to provide input to the host device over a microphone signal line. Such a headset may have a push button switch, (also referred to as a “microphone button”) to send a DC control signal to the host device over the microphone signal line. For example, actuating the switch sends a signal that instructs the host device to disconnect or hang up an ongoing phone call.